基于STM32的卷对卷空间隔离原子层沉积设备张力控制系统设计

为了改善卷对卷空间隔离原子层沉积设备由于柔性运输基板张力控制引起的薄膜产品质量降低的问题,设计了一种基于STM32的闭环张力自动控制系统以实现张力的精确控制。该系统通过张力传感器对张力进行实时检测,结合PID控制算法通过电气比例阀对气缸出力进行控制,从而实现对张力的闭环控制。将该系统应用在卷对卷空间隔离原子层沉积设备上并进行测试,结果表明:该张力控制系统具有良好的稳定性与可靠性,在设备静止工况下张力的稳态误差最低能达到5%以内,运动工况下的张力波动率最低能达到15%以内。并且在较好的张力控制下,薄膜的制造重复性与产品质量均得到显著改善。     

基于无矩理论的凹版印刷机运动薄膜横向振动特性及稳定性

研究了运动薄膜横向振动特性及其稳定性,以无矩理论为基础,建立了多色组印刷情况下具有中间刚性支承运动薄膜的横向振动模型。根据D'Alembert原理,建立了振动系统的运动微分方程。数值分析了薄膜的振动频率与运动速度、张力、支承位置之间的关系,结果表明中间单刚性支承薄膜振动发散失稳的临界速度为35.855 m/s。对于具有中间两刚性支承的印刷运动薄膜,薄膜轴向运动速度越低,支撑位置的变化对薄膜振动频率影响越明显。     

轴向运动带的横向与纵向非线性振动

研究轴向运动带的横向和纵向自由振动问题。利用Hamilton原理,建立轴向运动带横向和纵向自由振动的耦合动力学模型。基于Galerkin方法对轴向运动带系统模型的状态变量作离散,得到带有非线性项的常微分方程组。通过数值仿真,给出轴向运动带的横向振动与纵向振动比较,轴向运动速度对带的横向振动和纵向振动的影响,以及初张力对带的横向振动和纵向振动的影响。     

卷绕物收卷过程的F-V协调控制

在分析了卷绕物收卷过程运动特性的基础上，提出了卷绕控制中张力线速度（F-V）协调控制的重要性。从控制方式、执行机构和控制算法3个方面出发，对目前的控制方案进行了分析比较，列举了各种控制方案的优、缺点。在分析了交流力矩电动机的机械特性之后，结合收卷过程的运动特性，提出了F-V协调控制中采用交流力矩电动机作为执行机构、智能控制算法作为控制策略的一种发展趋势。     

卷料输送复合调偏机的设计及应用

卷料输送机是应用较多的一种输送机械，运行中常见也是较难解决的一种故障是卷料跑偏现象。卷料在输送过程中，由于机械的制造及安装误差、卷料厚薄不均及张力波动等各方面原因，会产生跑偏现象，影响后续工序的正常进行。通常在横向位置有一定要求的工序前设置卷料输送横向位置纠偏装置。文中叙述的复合调偏机较好地解决了输送带跑偏的问题。该复合调偏机现用于彩虹集团网板有限公司A5生产线上，运行良好，效果理想。     

光亮退火线生产过程钢卷卷径精准控制技术的研究与实现

对光亮退火线开卷机静态和动态卷径的测量提出新方法：静态卷径通过测量不同规格的钢卷，得到钢卷卷径和压辊编码器旋转角度的对应关系，从而拟合出近似的非线性卷径测量曲线；动态卷径根据角速度、线速度、旋转半径的对应关系，计算得出开卷机实时卷径。针对加减速过程中的辊面打滑，采用动态纠正机制减小了偏差。该项技术很大程度上提升了初始转矩给定值的精准控制，运行过程中确保张力和速度精度满足需求，提升了设备稳定性和产品质量。     

轴向加速度运动弦线横向振动的数值计算方法

讨论轴向加速度运动弦线横向振动的数学模型、数值计算方法等问题。基于Coriolis加速度和Iagrangian应力公式，利用Newton第二定律导出轴向加速度运动弦线横向振动的动力学模型；通过线性变换将方程化为一阶无量纲的非线性微分方程组；并利用Crank-Nicoson的中点离散技巧，给出运动方程的单步二阶差分方法；算法把对运动方程和本构方程分别离散，使之可以用于不同本构的运动弦线的数值仿真。且方法对线性问题绝对稳定，对非线性问题也有较好的稳定性。作为应用实例，利用该方法对一类加速度运动弦线的横向振动进行数值仿真，利用弹性弦线的守衡公式检验数值结果的精度。并利用给出的数值方法分析速度、加速度、弹性模量等参数对弦线横向振动的影响。     

输送带收卷装置设计及其恒张力控制研究

在带式输送机换带过程中,存在因输送带收卷张力不稳定造成的松卷或收卷电机过载等问题,对卷带机恒张力控制进行了研究,提出了一种卷带张力控制数学模型,通过该模型设计了一款中心收卷式卷带机,以及一种基于PI变频调速来实现恒张力收卷的控制策略。通过将卷带机模型进行简化,利用Recurdyn-R2R2D建立了卷带机简化后的动力学仿真模型,并根据张力控制模型在Colink联合仿真分析中搭建了输送带收卷恒张力控制策略;最终,对Recurdyn与Colink进行了联合仿真,分析了恒张力收卷效果。研究结果表明:运用张力控制模型设计的PI变频调速来实现恒张力收卷的控制策略,能够使带式输送机收卷过程中单位张力稳定在5 N/mm~2,且最大超调量不超过8%;并且能够感应收卷张力突增信号从而迅速控制卷带机停机,防止电机过载,为卷带机设计及现场运用提供了参考依据。     

高速织机经纱振动特性分析

针对经纱振动影响织机织造性能的问题,对高速织机织造过程中经纱的横向与纵向耦合振动进行了研究,建立了经纱横向和纵向振动的耦合动力学模型,通过采用弹性力学方法和非线性振动方法对经纱运动的波动过程进行了分析,针对织造过程中的经纱黏弹性本构关系,选用了Kelvin模型,根据牛顿定律建立了经纱横向与纵向的振动微分方程。并利用Galerkin方法离散运动方程,分离时间和空间变量,将复杂的偏微分方程转化为常微分方程,采用四阶龙格库塔方法和Matlab,仿真分析了经纱横向振动和纵向振动特性以及经纱参数对经纱振动的影响。研究结果表明:在经纱织造过程中,对于小振幅的经纱耦合振动,经纱纵向振动几乎不影响横向振动,通过改变相应的经纱参数能够有效地降低经纱振动频率,有效地防止了经纱断纱,为经纱有效振动控制提供了理论基础。     

壁纸收卷机张力控制系统设计与实现

在分析收卷过程中张力产生的原因及对张力要求的基础上,完成了一套闭环变张力控制系统的结构设计,以及主要控制算法和PLC程序的编写,通过使收卷电机PI控制中的比例系数和收卷张力随卷径而变化,满足了收卷张力的工艺需求,达到了稳定控制的目的。     

Design and implementation of adaptive PI control schemes for web tension control in roll-to-roll (R2R) manufacturing

In this paper, two adaptive Proportional-Integral (PI) control schemes are designed and discussed for control of web tension in Roll-to-Roll (R2R) manufacturing systems. R2R systems are used to transport continuous materials (called webs) on rollers from the unwind roll to the rewind roll. Maintaining web tension at the desired value is critical to many R2R processes such as printing, coating, lamination, etc. Existing fixed gain PI tension control schemes currently used in industrial practice require extensive tuning and do not provide the desired performance for changing operating conditions and material properties. The first adaptive PI scheme utilizes the model reference approach where the controller gains are estimated based on matching of the actual closed-loop tension control systems with an appropriately chosen reference model. The second adaptive PI scheme utilizes the indirect adaptive control approach together with relay feedback technique to automatically initialize the adaptive PI gains. These adaptive tension control schemes can be implemented on any R2R manufacturing system. The key features of the two adaptive schemes is that their designs are simple for practicing engineers, easy to implement in real-time, and automate the tuning process. Extensive experiments are conducted on a large experimental R2R machine which mimics many features of an industrial R2R machine. These experiments include trials with two different polymer webs and a variety of operating conditions. Implementation guidelines are provided for both adaptive schemes. Experimental results comparing the two adaptive schemes and a fixed gain PI tension control scheme used in industrial practice are provided and discussed.     

Influence of initial pressure on frequency characteristics of a rotating truncated circular conical shell

As a new global numerical approximate technique, the generalized differential quadrature (GDQ) method is used in this paper to study the influence of initial pressure load on the free vibration of a rotating thin isotropic truncated circular conical shell. The present motion governing equations include the influence of initial stress field due to the initial uniform pressure. The effects of initial hoop tension and the centrifugal and coriolis accelerations due to rotation are also considered. The influence of initial pressure on the frequency characteristics of the rotating conical shell is discussed in detail. For the examination of present work, frequency numerical comparisons are made with those available in published works, and very good agreement is achieved.     

Generalized differential quadrature for free vibration of rotating composite laminated conical shell with various boundary conditions

By using the generalized differential quadrature (GDQ) method, this paper presents the orthotropic influence of composite materials on frequency characteristics for a rotating thin truncated circular symmetrical cross-ply laminated composite conical shell with different boundary conditions. The present governing equations of free vibration include the effects of initial hoop tension and the centrifugal and Coriolis accelerations due to rotation. Frequency characteristics are obtained to study in detail the orthotropic influences. Effects of boundary condition, rotating speed, circumferential wave number and geometric property are also discussed. To ensure the accuracy of the present results by the GDQ method, comparisons are made with those available in open literature and very good agreements are achieved.     

轴向运动功能梯度梁的横向振动

新型非均匀复合材料,功能梯度材料具有防止脱层和减缓热应力等优良性能,将其应用于功能梯度梁的结构有着非常重要的工程应用价值。基于Euler-Bernoulli梁理论和Hamilton原理,建立轴向运动功能梯度梁横向自由振动的运动微分方程,其中假设功能梯度梁的材料特性沿梁厚度方向按各组分材料体积分数的幂函数连续变化;再对运动微分方程和边界条件进行量纲一处理,采用微分求积法对其进行离散化,导出系统的广义复特征方程,然后计算分析轴向运动功能梯度简支梁横向振动复频率的实部和虚部随量纲一轴向运动速度、梯度指标等参数的变化情况,并讨论量纲一轴向运动速度和梯度指标对功能梯度梁的横向振动特性以及失稳形式的影响。     

Vibration and crack detection of a rotor with speed-dependent bearings

The vibration of a shaft-disk rotor containing a transverse crack and supported by speed-dependent bearings is investigated. With crack released energy, the flexibility due to crack is first evaluated. An energy principle in conjunction with the assumed-mode method follow to yield the discrete equations of motion of periodic, time-varying coefficients From the FFT analysis of the displacement responses, the two-times shaft speed component (2Ω) is extracted and serves as a good index to detect the crack location and depth. Response amplitudes to the variations of crack depth and crack location are then discussed and a technique of crack identification is introduced with the aid of response contour maps of two sensing probes.     

多楔带传动系统的频率灵敏度分析

为了对实际多楔带传动系统进行振动分析与设计优化,系统地研究多楔带传动系统的固有频率对关键设计参数的灵敏度。给出反映带轮、张紧臂等离散部件转动振动与各段皮带这类移动弹性体横向振动之间彼此耦合的运动方程。根据方程耦合与否以及求解的需要将该系统一分为二。对于具有运动耦合的子系统,建立矩阵形式的自由振动方程,推导出固有频率对设计参数的灵敏度表达式,由此导出固有频率对自动张紧机构设计参数和皮带传动速度的灵敏度的显式计算式。针对一多楔带传动系统,计算固有频率对张紧臂长度、扭转弹簧刚度、安装角以及带速的灵敏度,并运用有限差分法结果予以验证。     

CSP轧机扭振中“伪拍振”的研究

某厂CSP轧机出现了严重的扭振.扭振具有拍振的特征.为摸清轧机振动规律进而解决轧机振动问题.对栽CSP轧机拍振进行了研究.测试分析和理论研究发现这是一种"伪拍振"现象,"伪拍振"的形成是由于工作辊辊面局部区域有振纹存在.振纹区域与轧件接触时,轧机以振纹频率做强迫振动;没有振纹的辊面区域与轧件接触时,因负阻尼作用,系统表现为固有频率下的自激振动.两种振动形式交替出现,且振动强度大小不同,使扭振表现出"拍振"的形态.上述发现对轧机的振动机理及其抑制措施的研究有重要价值.试验证明,据此提出的使用高速钢轧辊等抑制振动措施有很好的效果.     

主被动约束层阻尼在结构振动控制中的应用与设计

导出了自感知主被动阻尼控制梁结构的振动控制方程。引入速度负反馈形成闭环控制,对被动控制和主被动控制的控制效果进行了分析比较。分析了粘弹层、压电层厚度和压电片位置等结构参数变化以及材料参数变化对控制效果及结构频率的影响。并分析了主被动阻尼控制结构的特点和设计中应注意的问题。     

Design and Analysis of a Novel Tension Control Method for Winding Machine

Filament winding has emerged as the main process for carbon fiber reinforced plastic(CFRP) fabrication, and tension control plays a key role in enhancing the quality of the winding products. With the continuous improvement of prod?uct quality and e ciency, the precision of the tension control system is constantly improving. In this paper, a novel tension control method is proposed, which can regulate the fiber tension and transport speed of the winding process by governing the outputs of three di erent driven rollers(the torque of the unwind roll, the torque of the magnetic powder brake roller, and the speed of the master speed roller) in three levels. The mechanical structures and dynamic models of the driven rollers and idle rollers are established by considering the time?varying features of the roller radius and inertia. Moreover, the influence of parameters and speed variation on fiber tension is investigated using the increment model. Subsequently, the control method is proposed by applying fiber tension in three levels accord?ing to the features of the three driven rollers. An adaptive fuzzy controller is designed for tuning the PID parameters online to control the speed of the master speed roller. Simulation is conducted for verifying the performance and sta?bility of the proposed tension control method by comparing with those of the conventional PID control method. The result reveals that the proposed method outperforms the conventional method. Finally, an experimental platform is constructed, and the proposed system is applied to a winding machine. The performance and stability of the tension control system are demonstrated via a series of experiments using carbon fiber under di erent reference speeds and tensions. This paper proposes a novel tension control method to regulate the fiber tension and transport speed.